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Franco Nitta C, Green EW, Jhamba ED, Keth JM, Ortiz-Caraveo I, Grattan RM, Schodt DJ, Gibson AC, Rajput A, Lidke KA, Wilson BS, Steinkamp MP, Lidke DS. EGFR transactivates RON to drive oncogenic crosstalk. eLife 2021; 10:63678. [PMID: 34821550 PMCID: PMC8654365 DOI: 10.7554/elife.63678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/24/2021] [Indexed: 12/22/2022] Open
Abstract
Crosstalk between different receptor tyrosine kinases (RTKs) is thought to drive oncogenic signaling and allow therapeutic escape. EGFR and RON are two such RTKs from different subfamilies, which engage in crosstalk through unknown mechanisms. We combined high-resolution imaging with biochemical and mutational studies to ask how EGFR and RON communicate. EGF stimulation promotes EGFR-dependent phosphorylation of RON, but ligand stimulation of RON does not trigger EGFR phosphorylation – arguing that crosstalk is unidirectional. Nanoscale imaging reveals association of EGFR and RON in common plasma membrane microdomains. Two-color single particle tracking captured formation of complexes between RON and EGF-bound EGFR. Our results further show that RON is a substrate for EGFR kinase, and that transactivation of RON requires formation of a signaling competent EGFR dimer. These results support a role for direct EGFR/RON interactions in propagating crosstalk, such that EGF-stimulated EGFR phosphorylates RON to activate RON-directed signaling.
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Affiliation(s)
| | - Ellen W Green
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - Elton D Jhamba
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - Justine M Keth
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - Iraís Ortiz-Caraveo
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - Rachel M Grattan
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - David J Schodt
- Department of Physics & Astronomy, University of New Mexico, Albuquerque, United States
| | - Aubrey C Gibson
- Department of Pathology, University of New Mexico, Albuquerque, United States
| | - Ashwani Rajput
- Department of Surgery, University of New Mexico, Albuquerque, United States.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, United States
| | - Keith A Lidke
- Department of Physics & Astronomy, University of New Mexico, Albuquerque, United States.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, United States
| | - Bridget S Wilson
- Department of Pathology, University of New Mexico, Albuquerque, United States.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, United States
| | - Mara P Steinkamp
- Department of Pathology, University of New Mexico, Albuquerque, United States.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, United States
| | - Diane S Lidke
- Department of Pathology, University of New Mexico, Albuquerque, United States.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, United States
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Gasco V, Cambria V, Bioletto F, Ghigo E, Grottoli S. Traumatic Brain Injury as Frequent Cause of Hypopituitarism and Growth Hormone Deficiency: Epidemiology, Diagnosis, and Treatment. Front Endocrinol (Lausanne) 2021; 12:634415. [PMID: 33790864 PMCID: PMC8005917 DOI: 10.3389/fendo.2021.634415] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/16/2021] [Indexed: 12/12/2022] Open
Abstract
Traumatic brain injury (TBI)-related hypopituitarism has been recognized as a clinical entity for more than a century, with the first case being reported in 1918. However, during the 20th century hypopituitarism was considered only a rare sequela of TBI. Since 2000 several studies strongly suggest that TBI-mediated pituitary hormones deficiency may be more frequent than previously thought. Growth hormone deficiency (GHD) is the most common abnormality, followed by hypogonadism, hypothyroidism, hypocortisolism, and diabetes insipidus. The pathophysiological mechanisms underlying pituitary damage in TBI patients include a primary injury that may lead to the direct trauma of the hypothalamus or pituitary gland; on the other hand, secondary injuries are mainly related to an interplay of a complex and ongoing cascade of specific molecular/biochemical events. The available data describe the importance of GHD after TBI and its influence in promoting neurocognitive and behavioral deficits. The poor outcomes that are seen with long standing GHD in post TBI patients could be improved by GH treatment, but to date literature data on the possible beneficial effects of GH replacement therapy in post-TBI GHD patients are currently scarce and fragmented. More studies are needed to further characterize this clinical syndrome with the purpose of establishing appropriate standards of care. The purpose of this review is to summarize the current state of knowledge about post-traumatic GH deficiency.
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Oh HS, Oh SK, Lee JS, Wu C, Lee SJ. Effects of l-arginine on growth hormone and insulin-like growth factor 1. Food Sci Biotechnol 2017; 26:1749-1754. [PMID: 30263714 DOI: 10.1007/s10068-017-0236-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/03/2017] [Accepted: 07/05/2017] [Indexed: 10/18/2022] Open
Abstract
l-Arginine has been reported to promote cellular and organismal growth. In this study, the effects of l-arginine on the expression of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), the two key growth factors, are investigated in cultured GH3 pituitary epithelium and HepG2 cells, respectively. l-Arginine significantly induced the gene expression of GH and IGF-1 in GH3 pituitary epithelium and HepG2 hepatocytes respectively, and reduced IGF binding protein-1 gene expression in HepG2 cells assessed via quantitative polymerase chain reaction analysis. l-Arginine also significantly induced GH and IGF-1 hormone secretion from GH3 and HepG2 cells, respectively. In addition, the multi-target ELISA analysis conducted revealed that phosphorylation of p-38 MAPK, MEK, and JNK were significantly increased in HepG2 cells, suggesting l-arginine-induced activation of the MAPK signaling pathway. These results suggest that l-arginine promotes the synthesis and secretion of GH and IGF-1 in vitro and induces the MAPK signaling cascade in cultured hepatocytes.
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Affiliation(s)
- Hyun-Seok Oh
- 1Department of Biotechnology, School of Life Sciences and Biotechnology for BK21 PLUS, Korea University, Seoul, 02841 Korea
| | - Se Kwan Oh
- 2Rice Research Division, National Institute of Crop Science, Rural Development Administration, Suwon, 441-857 Korea
| | - Jum Seek Lee
- 2Rice Research Division, National Institute of Crop Science, Rural Development Administration, Suwon, 441-857 Korea
| | - Chunyan Wu
- 1Department of Biotechnology, School of Life Sciences and Biotechnology for BK21 PLUS, Korea University, Seoul, 02841 Korea
| | - Sung-Joon Lee
- 1Department of Biotechnology, School of Life Sciences and Biotechnology for BK21 PLUS, Korea University, Seoul, 02841 Korea
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4
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González L, Miquet JG, Irene PE, Díaz ME, Rossi SP, Sotelo AI, Frungieri MB, Hill CM, Bartke A, Turyn D. Attenuation of epidermal growth factor (EGF) signaling by growth hormone (GH). J Endocrinol 2017; 233:175-186. [PMID: 28223314 DOI: 10.1530/joe-16-0606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 02/21/2017] [Indexed: 01/20/2023]
Abstract
Transgenic mice overexpressing growth hormone (GH) show increased hepatic protein content of the epidermal growth factor receptor (EGFR), which is broadly associated with cell proliferation and oncogenesis. However, chronically elevated levels of GH result in desensitization of STAT-mediated EGF signal and similar response of ERK1/2 and AKT signaling to EGF compared to normal mice. To ascertain the mechanisms involved in GH attenuation of EGF signaling and the consequences on cell cycle promotion, phosphorylation of signaling mediators was studied at different time points after EGF stimulation, and induction of proteins involved in cell cycle progression was assessed in normal and GH-overexpressing transgenic mice. Results from kinetic studies confirmed the absence of STAT3 and 5 activation and comparable levels of ERK1/2 phosphorylation upon EGF stimulation, which was associated with diminished or similar induction of c-MYC, c-FOS, c-JUN, CYCLIN D1 and CYCLIN E in transgenic compared to normal mice. Accordingly, kinetics of EGF-induced c-SRC and EGFR phosphorylation at activating residues demonstrated that activation of these proteins was lower in the transgenic mice with respect to normal animals. In turn, EGFR phosphorylation at serine 1046/1047, which is implicated in the negative regulation of the receptor, was increased in the liver of GH-overexpressing transgenic mice both in basal conditions and upon EGF stimulus. Increased basal phosphorylation and activation of the p38-mitogen-activated protein kinase might account for increased Ser 1046/1047 EGFR. Hyperphosphorylation of EGFR at serine residues would represent a compensatory mechanism triggered by chronically elevated levels of GH to mitigate the proliferative response induced by EGF.
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Affiliation(s)
- Lorena González
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Johanna G Miquet
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Pablo E Irene
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - M Eugenia Díaz
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Soledad P Rossi
- Instituto de Biología y Medicina ExperimentalCONICET, Ciudad de Buenos Aires, Argentina
| | - Ana I Sotelo
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Mónica B Frungieri
- Instituto de Biología y Medicina ExperimentalCONICET, Ciudad de Buenos Aires, Argentina
| | - Cristal M Hill
- Departments of Internal Medicine and PhysiologyGeriatrics Research, School of Medicine, Southern Illinois University, Springfield, Illinois, USA
| | - Andrzej Bartke
- Departments of Internal Medicine and PhysiologyGeriatrics Research, School of Medicine, Southern Illinois University, Springfield, Illinois, USA
| | - Daniel Turyn
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET)Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
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5
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Cheung AKL, Ip JCY, Chu ACH, Cheng Y, Leong MML, Ko JMY, Shuen WH, Lung HL, Lung ML. PTPRG suppresses tumor growth and invasion via inhibition of Akt signaling in nasopharyngeal carcinoma. Oncotarget 2016; 6:13434-47. [PMID: 25970784 PMCID: PMC4537025 DOI: 10.18632/oncotarget.3876] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/03/2015] [Indexed: 01/01/2023] Open
Abstract
Protein Tyrosine Phosphatase, Receptor Type G (PTPRG) was identified as a candidate tumor suppressor gene in nasopharyngeal carcinoma (NPC). PTPRG induces significant in vivo tumor suppression in NPC. We identified EGFR as a PTPRG potential interacting partner and examined this interaction. Dephosphorylation of EGFR at EGFR-Y1068 and -Y1086 sites inactivated the PI3K/Akt signaling cascade and subsequent down-regulation of downstream pro-angiogenic and -invasive proteins (VEGF, IL6, and IL8) and suppressed tumor cell proliferation, angiogenesis, and invasion. The effect of Akt inhibition in NPC cells was further validated by Akt knockdown experiments in the PTPRG-down-regulated NPC cell lines. Our results suggested that inhibition of Akt in NPC cells induces tumor suppression at both the in vitro and in vivo levels, and also importantly, in vivo metastasis. In conclusion, we confirmed the vital role of PTPRG in inhibiting Akt signaling with the resultant suppression of in vivo tumorigenesis and metastasis.
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Affiliation(s)
- Arthur Kwok Leung Cheung
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Centre for Cancer Research, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Joseph Chok Yan Ip
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Adrian Chi Hang Chu
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Yue Cheng
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Centre for Cancer Research, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Merrin Man Long Leong
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Josephine Mun Yee Ko
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Wai Ho Shuen
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Division of Medical Oncology, National Cancer Centre, Singapore
| | - Hong Lok Lung
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Centre for Cancer Research, University of Hong Kong, Hong Kong (SAR), People's Republic of China
| | - Maria Li Lung
- Department of Clinical Oncology, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Centre for Cancer Research, University of Hong Kong, Hong Kong (SAR), People's Republic of China.,Centre for Nasopharyngeal Carcinoma Research, University of Hong Kong, Hong Kong (SAR), People's Republic of China
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6
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Tao HC, Wang HX, Dai M, Gu CY, Wang Q, Han ZG, Cai B. Targeting SHCBP1 inhibits cell proliferation in human hepatocellular carcinoma cells. Asian Pac J Cancer Prev 2015; 14:5645-50. [PMID: 24289556 DOI: 10.7314/apjcp.2013.14.10.5645] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Src homology 2 domain containing (SHC) is a proto-oncogene which mediates cell proliferation and carcinogenesis in human carcinomas. Here, the SHC SH2-domain binding protein 1 (SHCBP1) was first established to be up-regulated in human hepatocellular carcinoma (HCC) tissues by array-base comparative genome hybridization (aCGH). Meanwhile, we examine and verify it by quantitative real-time PCR and western blot. Our current data show that SHCBP1 was up-regulated in HCC tissues. Overexpression of SHCBP1 could significantly promote HCC cell proliferation, survival and colony formation in HCC cell lines. Furthermore, knockdown of SHCBP1 induced cell cycle delay and suppressed cell proliferation. Furthermore, SHCBP1 could regulate the expression of activate extracellular signal-regulated kinase 1/2 (ERK1/2) and cyclin D1. Together, our findings indicate that SHCBP1 may contribute to human hepatocellular carcinoma by promoting cell proliferation and may serve as a molecular target of cancer therapy.
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Affiliation(s)
- Han-Chuan Tao
- Department of Hepatobiliary Surgery, Wuxi Municipal People's Hospital of Nanjing Medical University, Wuxi, China E-mail : ,
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7
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Collin de l'Hortet A, Zerrad-Saadi A, Prip-Buus C, Fauveau V, Helmy N, Ziol M, Vons C, Billot K, Baud V, Gilgenkrantz H, Guidotti JE. GH administration rescues fatty liver regeneration impairment by restoring GH/EGFR pathway deficiency. Endocrinology 2014; 155:2545-54. [PMID: 24708244 DOI: 10.1210/en.2014-1010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
GH pathway has been shown to play a major role in liver regeneration through the control of epidermal growth factor receptor (EGFR) activation. This pathway is down-regulated in nonalcoholic fatty liver disease. Because regeneration is known to be impaired in fatty livers, we wondered whether a deregulation of the GH/EGFR pathway could explain this deficiency. Hepatic EGFR expression and triglyceride levels were quantified in liver biopsies of 32 obese patients with different degrees of steatosis. We showed a significant inverse correlation between liver EGFR expression and the level of hepatic steatosis. GH/EGFR down-regulation was also demonstrated in 2 steatosis mouse models, a genetic (ob/ob) and a methionine and choline-deficient diet mouse model, in correlation with liver regeneration defect. ob/ob mice exhibited a more severe liver regeneration defect after partial hepatectomy (PH) than methionine and choline-deficient diet-fed mice, a difference that could be explained by a decrease in signal transducer and activator of transcription 3 phosphorylation 32 hours after PH. Having checked that GH deficiency accounted for the GH signaling pathway down-regulation in the liver of ob/ob mice, we showed that GH administration in these mice led to a partial rescue in hepatocyte proliferation after PH associated with a concomitant restoration of liver EGFR expression and signal transducer and activator of trnascription 3 activation. In conclusion, we propose that the GH/EGFR pathway down-regulation is a general mechanism responsible for liver regeneration deficiency associated with steatosis, which could be partially rescued by GH administration.
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Affiliation(s)
- A Collin de l'Hortet
- Inserm (A.C.H., A.Z.-S., C.P.-B., V.F., N.H., C.V., K.B., V.B., H.G., J.-E.G.), U1016, Institut Cochin, 75014, Paris, France; CNRS (A.C.H., A.Z.-S., C.P.-B., V.F., N.H., C.V., K.B., V.B., H.G., J.-E.G.), UMR8104, 75014, Paris, France; Université Paris Descartes (A.C.H., A.Z.-S., C.P.-B., V.F., N.H., C.V., K.B., V.B., H.G., J.-E.G.), Sorbonne Paris Cité, Faculté de Médecine 75006, Paris, France; and Service de Chirurgie Digestive et Métabolique (N.H., M.Z., C.V.), Assistance Publique-Hôpitaux de Paris, Hôpitaux Universitaires Paris-Seine-St-Denis, Hôpital Jean Verdier, 93140, Bondy, France
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8
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Felice DL, El-Shennawy L, Zhao S, Lantvit DL, Shen Q, Unterman TG, Swanson SM, Frasor J. Growth hormone potentiates 17β-estradiol-dependent breast cancer cell proliferation independently of IGF-I receptor signaling. Endocrinology 2013; 154:3219-27. [PMID: 23782942 PMCID: PMC3749474 DOI: 10.1210/en.2012-2208] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Estrogen action in mammary gland development and breast cancer progression is tightly linked to the GH/IGF-I axis. Although many of the effects of GH on mammary gland growth and development require IGF-I, the extent to which GH action in breast cancer depends on IGF-I is not known. We examined GH action in a panel of estrogen receptor-positive breast cancer cell lines and found that T47D cells express significant levels of GH receptor and that GH significantly enhances 17β-estradiol (E2)-stimulated proliferation in these cells. GH action in the T47D cells was independent of changes in IGF-I and IGF-I receptor (IGF-IR) expression and IGF-IR signaling, suggesting that GH can exert direct effects on breast cancer cells. Although E2-dependent proliferation required IGF-IR signaling, the combination of GH+E2 overcame inhibition of IGF-IR activity to restore proliferation. In contrast, GH required both Janus kinase 2 and epidermal growth factor receptor signaling for subsequent ERK activation and potentiation of E2-dependent proliferation. Downstream of these pathways, we identified a number of immediate early-response genes associated with proliferation that are rapidly and robustly up-regulated by GH. These findings demonstrate that GH can have important effects in breast cancer cells that are distinct from IGF-IR activity, suggesting that novel drugs or improved combination therapies targeting estrogen receptor and the GH/IGF axis may be beneficial for breast cancer patients.
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Affiliation(s)
- Dana L Felice
- Department of Physiology and Biophysics, University of Illinois at Chicago, 835 South Wolcott Avenue, MC 901, Chicago, Illinois 60612, USA
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9
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Esposito DL, Verginelli F, Toracchio S, Mammarella S, De Lellis L, Vanni C, Russo A, Mariani-Costantini R, Cama A. Novel insulin receptor substrate 1 and 2 variants in breast and colorectal cancer. Oncol Rep 2013; 30:1553-60. [PMID: 23877285 PMCID: PMC3810354 DOI: 10.3892/or.2013.2626] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/05/2013] [Indexed: 12/11/2022] Open
Abstract
The insulin/insulin-like growth factor pathway is involved in breast and colorectal cancer (CRC) development. In the present study, we analyzed the coding region and short intron-exon borders of the insulin receptor substrate 1 and 2 (IRS-1 and IRS-2) genes in 12 cell lines derived from breast cancer (BC), 14 cell lines derived from CRC and 33 primary CRCs. The nucleotide variants identified in BC were 3 in IRS-1, 1 of which (p.Arg267Cys) was novel and with a pathogenic potential as predicted by in silico analysis and 6 in IRS-2. Twenty-one variants in IRS-1 and 18 in IRS-2 were identified in the CRC samples. These included 11 novel IRS-1 variants detected exclusively in CRCs, which included 5 missense (p.Pro559Leu, p.Gln655His, p.Asp1014Gly, p.Asp1181His and pPro1203Ser) with a pathogenic potential as predicted by in silico analysis, 2 frameshifts predicted to generate a truncated protein, 1 splice-site mutation and 3 silent variants. In the CRC samples we also identified 7 novel IRS-2 variants, including 4 missense variants, which included 2 (p.Asp782Asn and p.Gly1230Ser) with a pathogenic potential as predicted by in silico analysis, 2 frame insertion mutations and 1 silent variant. Most of the novel IRS-1 and IRS-2 variants may be involved in the modulation of IRS-1 or IRS-2 functions and could be relevant to breast and colorectal tumorigenesis.
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Affiliation(s)
- Diana Liberata Esposito
- Unit of General Pathology, Aging Research Center, G. d'Annunzio University Foundation, I‑66100 Chieti, Italy.
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Devesa J, Reimunde P, Devesa P, Barberá M, Arce V. Growth hormone (GH) and brain trauma. Horm Behav 2013; 63:331-44. [PMID: 22405763 DOI: 10.1016/j.yhbeh.2012.02.022] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/21/2012] [Accepted: 02/22/2012] [Indexed: 12/27/2022]
Abstract
Growth hormone (GH) is a pleiotropic hormone with known neurotrophic effects. We aimed to study whether GH administration might be useful together with rehabilitation in the recovery of TBI patients. 13 TBI patients (8 M, 5 F; age: 6-53 years old) were studied. Time after TBI: 2.5 months to 11 years; 5 patients showed acquired GH-deficiency (GHD). Disabilities observed: cognitive disorders; motor plegias; neurogenic dysphagia (n=5), vegetative coma (n=2) and amaurosis (n=1). All but one TBI patient followed intense rehabilitation for years. Treatment consisted of GH administration (maximal dose 1 mg/day, 5 days/week, resting 15-days every 2-months, until a maximum of 8 months) and clinical rehabilitation according to the individual needs (3-4 h/day, 5 days/week, during 6-12 months). Informed consent was obtained before commencing GH administration. GH significantly increased plasma IGF-1 values (ng.mL(-1)) in both GHD and no GHD patients, being then similar between both groups (GHD: 275.6±35.6 [p<0.01 vs. baseline], no GHD: 270.2±64 [p<0.05 vs. baseline]). In all the cases clear significant improvements were observed during and at the end of the combined treatment. Cognitive improvements appeared earlier and were more important than motor improvements. Swallowing improved significantly in all TBI patients with neurogenic dysphagia (2 of them in a vegetative state). Visual performance was ameliorated in the patient with amaurosis. No undesirable side-effects were observed. Our data indicate that GH can be combined with rehabilitation for improving disabilities in TBI patients, regardless of whether or not they are GHD.
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Affiliation(s)
- Jesús Devesa
- Department of Physiology, School of Medicine, University of Santiago de Compostela, Spain.
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11
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Qu WS, Tian DS, Guo ZB, Fang J, Zhang Q, Yu ZY, Xie MJ, Zhang HQ, Lü JG, Wang W. Inhibition of EGFR/MAPK signaling reduces microglial inflammatory response and the associated secondary damage in rats after spinal cord injury. J Neuroinflammation 2012; 9:178. [PMID: 22824323 PMCID: PMC3418570 DOI: 10.1186/1742-2094-9-178] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 07/02/2012] [Indexed: 02/08/2023] Open
Abstract
Background Emerging evidence indicates that reactive microglia-initiated inflammatory responses are responsible for secondary damage after primary traumatic spinal cord injury (SCI); epidermal growth factor receptor (EGFR) signaling may be involved in cell activation. In this report, we investigate the influence of EGFR signaling inhibition on microglia activation, proinflammatory cytokine production, and the neuronal microenvironment after SCI. Methods Lipopolysaccharide-treated primary microglia/BV2 line cells and SCI rats were used as model systems. Both C225 and AG1478 were used to inhibit EGFR signaling activation. Cell activation and EGFR phosphorylation were observed after fluorescent staining and western blot. Production of interleukin-1beta (IL-1β) and tumor necrosis factor alpha (TNFα) was tested by reverse transcription PCR and ELISA. Western blot was performed to semi-quantify the expression of EGFR/phospho-EGFR, and phosphorylation of Erk, JNK and p38 mitogen-activated protein kinases (MAPK). Wet-dry weight was compared to show tissue edema. Finally, axonal tracing and functional scoring were performed to show recovery of rats. Results EGFR phosphorylation was found to parallel microglia activation, while EGFR blockade inhibited activation-associated cell morphological changes and production of IL-1β and TNFα. EGFR blockade significantly downregulated the elevated MAPK activation after cell activation; selective MAPK inhibitors depressed production of cytokines to a certain degree, suggesting that MAPK mediates the depression of microglia activation brought about by EGFR inhibitors. Subsequently, seven-day continual infusion of C225 or AG1478 in rats: reduced the expression of phospho-EGFR, phosphorylation of Erk and p38 MAPK, and production of IL-1β and TNFα; lessened neuroinflammation-associated secondary damage, like microglia/astrocyte activation, tissue edema and glial scar/cavity formation; and enhanced axonal outgrowth and functional recovery. Conclusions These findings indicate that inhibition of EGFR/MAPK suppresses microglia activation and associated cytokine production; reduces neuroinflammation-associated secondary damage, thus provides neuroprotection to SCI rats, suggesting that EGFR may be a therapeutic target, and C225 and AG1478 have potential for use in SCI treatment.
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Affiliation(s)
- Wen-Sheng Qu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
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12
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EGFR: A Master Piece in G1/S Phase Transition of Liver Regeneration. Int J Hepatol 2012; 2012:476910. [PMID: 23050157 PMCID: PMC3461622 DOI: 10.1155/2012/476910] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 07/11/2012] [Indexed: 02/07/2023] Open
Abstract
Unraveling the molecular clues of liver proliferation has become conceivable thanks to the model of two-third hepatectomy. The synchronicity and the well-scheduled aspect of this process allow scientists to slowly decipher this mystery. During this phenomenon, quiescent hepatocytes of the remnant lobes are able to reenter into the cell cycle initiating the G1-S progression synchronously before completing the cell cycle. The major role played by this step of the cell cycle has been emphasized by loss-of-function studies showing a delay or a lack of coordination in the hepatocytes G1-S progression. Two growth factor receptors, c-Met and EGFR, tightly drive this transition. Due to the level of complexity surrounding EGFR signaling, involving numerous ligands, highly controlled regulations and multiple downstream pathways, we chose to focus on the EGFR pathway for this paper. We will first describe the EGFR pathway in its integrity and then address its essential role in the G1/S phase transition for hepatocyte proliferation. Recently, other levels of control have been discovered to monitor this pathway, which will lead us to discuss regulations of the EGFR pathway and highlight the potential effect of misregulations in pathologies.
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Díaz ME, González L, Miquet JG, Martínez CS, Sotelo AI, Bartke A, Turyn D. Growth hormone modulation of EGF-induced PI3K-Akt pathway in mice liver. Cell Signal 2011; 24:514-523. [PMID: 22019461 DOI: 10.1016/j.cellsig.2011.10.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 10/07/2011] [Accepted: 10/08/2011] [Indexed: 12/20/2022]
Abstract
The epidermal growth factor (EGF) activates the phosphatidylinositol 3-kinase (PI3K)-Akt cascade among other signaling pathways. This route is involved in cell proliferation and survival, therefore, its dysregulation can promote cancer. Considering the relevance of the PI3K-Akt signaling in cell survival and in the pathogenesis of cancer, and that GH was reported to modulate EGFR expression and signaling, the objective of this study was to analyze the effects of increased GH levels on EGF-induced PI3K-Akt signaling. EGF-induced signaling was evaluated in the liver of GH-overexpressing transgenic mice and in their normal siblings. While Akt expression was increased in GH-overexpressing mice, EGF-induced phosphorylation of Akt, relative to its protein content, was diminished at Ser473 and inhibited at Thr308; consequently, mTOR, which is a substrate of Akt, was not activated by EGF. However, the activation of PDK1, a kinase involved in Akt phosphorylation at Thr308, was not reduced in transgenic mice. Kinetics studies of EGF-induced Akt phosphorylation showed that it is rapidly and transiently induced in GH-overexpressing mice compared with normal siblings. Thus, the expression and activity of phosphatases involved in the termination of the PI3K-Akt signaling were studied. In transgenic mice, neither PTEN nor PP2A were hyperactivated; however, EGF induced the rapid and transient association of SHP-2 to Gab1, which mediates association to EGFR and activation of PI3K. Rapid recruitment of SHP2, which would accelerate the termination of the proliferative signal induced, could be therefore contributing to the diminished EGF-induced activity of Akt in GH-overexpressing mice.
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Affiliation(s)
- Ma Eugenia Díaz
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina
| | - Lorena González
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina.
| | - Johanna G Miquet
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina
| | - Carolina S Martínez
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina
| | - Ana I Sotelo
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina
| | - Andrzej Bartke
- Geriatrics Research, Departments of Internal Medicine and Physiology, School of Medicine, Southern Illinois University, Springfield, IL 62794, USA
| | - Daniel Turyn
- Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Junín 956 (1113) Buenos Aires, Argentina
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Kitai Y, Fukuda H, Enomoto T, Asakawa Y, Suzuki T, Inouye S, Handa H. Cell selective targeting of a simian virus 40 virus-like particle conjugated to epidermal growth factor. J Biotechnol 2011; 155:251-6. [DOI: 10.1016/j.jbiotec.2011.06.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/19/2011] [Accepted: 06/24/2011] [Indexed: 11/30/2022]
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15
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Zerrad-Saadi A, Lambert-Blot M, Mitchell C, Bretes H, Collin de l'Hortet A, Baud V, Chereau F, Sotiropoulos A, Kopchick JJ, Liao L, Xu J, Gilgenkrantz H, Guidotti JE. GH receptor plays a major role in liver regeneration through the control of EGFR and ERK1/2 activation. Endocrinology 2011; 152:2731-41. [PMID: 21540290 DOI: 10.1210/en.2010-1193] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
GH is a pleiotropic hormone that plays a major role in proliferation, differentiation, and metabolism via its specific receptor. It has been previously suggested that GH signaling pathways are required for normal liver regeneration but the molecular mechanisms involved have yet to be determined. The aim of this study was to identify the mechanisms by which GH controls liver regeneration. We performed two thirds partial hepatectomies in GH receptor (GHR)-deficient mice and wild-type littermates and showed a blunted progression in the G(1)/S transition phase of the mutant hepatocytes. This impaired liver regeneration was not corrected by reestablishing IGF-1 expression. Although the initial response to partial hepatectomy at the priming phase appeared to be similar between mutant and wild-type mice, cell cycle progression was significantly blunted in mutant mice. The main defect in GHR-deficient mice was the deficiency of the epidermal growth factor receptor activation during the process of liver regeneration. Finally, among the pathways activated downstream of GHR during G(1) phase progression, namely Erk1/2, Akt, and signal transducer and activator of transcription 3, we only found a reduced Erk1/2 phosphorylation in mutant mice. In conclusion, our results demonstrate that GH signaling plays a major role in liver regeneration and strongly suggest that it acts through the activation of both epidermal growth factor receptor and Erk1/2 pathways.
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Affiliation(s)
- Amal Zerrad-Saadi
- Institut Cochin, Inserm U.1016, Département Endocrinologie, Metabolisme et Cancer, 24 rue du Faubourg Saint Jacques, 75014 Paris, France
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16
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González L, Díaz ME, Miquet JG, Sotelo AI, Fernández D, Dominici FP, Bartke A, Turyn D. GH modulates hepatic epidermal growth factor signaling in the mouse. J Endocrinol 2010; 204:299-309. [PMID: 20032199 PMCID: PMC4208314 DOI: 10.1677/joe-09-0372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Epidermal growth factor (EGF) is a key regulator of cell survival and proliferation involved in the pathogenesis and progression of different types of cancer. The EGF receptor (EGFR) is activated by binding of the specific ligand but also by transactivation triggered by different growth factors including GH. Chronically, elevated GH levels have been associated with the progression of hepatocellular carcinoma. Considering EGF and GH involvement in cell proliferation and their signaling crosstalk, the objective of the present study was to analyze GH modulatory effects on EGF signaling in liver. For this purpose, GH receptor-knockout (GHR-KO) and GH-overexpressing transgenic mice were used. EGFR content was significantly decreased in GHR-KO mice. Consequently, EGF-induced phosphorylation of EGFR, AKT, ERK1/2, STAT3, and STAT5 was significantly decreased in these mice. In contrast, EGFR content as well as its basal tyrosine phosphorylation was increased in transgenic mice overexpressing GH. However, EGF stimulation caused similar levels of EGFR, AKT, and ERK1/2 phosphorylation in normal and transgenic mice, while EGF induction of STAT3 and STAT5 phosphorylation was inhibited in the transgenic mice. Desensitization of the STATs was related to decreased association of these proteins to the EGFR and increased association between STAT5 and the tyrosine phosphatase SH2-containing phosphatase-2. While GHR knockout is associated with diminished expression of the EGFR and a concomitant decrease in EGF signaling, GH overexpression results in EGFR overexpression with different effects depending on the signaling pathway analyzed: AKT and ERK1/2 pathways are induced by EGF, while STAT3 and STAT5 activation is heterologously desensitized.
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Affiliation(s)
- Lorena González
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina.
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17
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Growth factors improve neurogenesis and outcome after focal cerebral ischemia. J Neural Transm (Vienna) 2010; 116:1397-402. [PMID: 19826899 DOI: 10.1007/s00702-009-0329-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Accepted: 09/22/2009] [Indexed: 12/12/2022]
Abstract
Stem cells have been proposed as a new form of cell-based therapy in a variety of disorders, including acute and degenerative brain diseases. Endogenous neural stem cells (eNSC) reside in the subventricular zone and in the subgranular zone of the hippocampus. eNSC are capable of self-renewal and differentiation into functional glia and neurons. Unfortunately, spontaneous brain regeneration is inefficient for clinically significant improvement following brain injury. However, eNSC responses may be augmented considerably by perturbing the pathways governing cell proliferation, migration and differentiation by application of exogenous growth factors. Importantly, current evidence suggests that such perturbations may lead to better functional outcome after stroke. This article summarizes the progress made in this field.
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18
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Carroll RE, Goodlad RA, Poole AJ, Tyner AL, Robey RB, Swanson SM, Unterman TG. Reduced susceptibility to azoxymethane-induced aberrant crypt foci formation and colon cancer in growth hormone deficient rats. Growth Horm IGF Res 2009; 19:447-456. [PMID: 19406679 PMCID: PMC3005240 DOI: 10.1016/j.ghir.2009.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 02/06/2009] [Accepted: 02/11/2009] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To evaluate the role of GH in colon carcinogenesis, we examined the formation of aberrant crypt foci (ACFs) and tumor development in wild type (WT) and GH-deficient, spontaneous dwarf rats (SDRs) exposed to the carcinogen azoxymethane (AOM). DESIGN ACF were quantified by stereomicroscopy and tumor number and weights were recorded for each animal. Cell proliferation was measured by vincristine metaphase arrest, flow cytometry, and bromodeoxyuridine (BrdU) incorporation. Apoptosis was measured by TUNEL staining and cleaved caspase-3 immunohistochemistry. IGF-I was measured by radioimmunoassay (RIA). Hexokinase activity was measured by spectrophotometric assay. PARP cleavage, and IGF-IR, and p27(kip/cip) expression were measured by Western blotting. RESULTS ACFs detected by stereomicroscopy were markedly reduced ( approximately 85%) in SDRs vs. WT rats at 10, 25, and 28 weeks after AOM. Tumor incidence, number, and weight also were reduced in SDR vs. WT animals. AOM treatment increased cell proliferation in the distal colon (where tumors occur) of WT rats but not SDRs, and these changes corresponded to increased ACF and tumor formation. Apoptosis rates were similar in AOM-treated WT and SDRs. Alterations in serum IGF-I levels may contribute to differences in the proliferative response to AOM and decreased ACF formation in SDR vs. WT rats. CONCLUSIONS We conclude that early neoplastic lesions (ACFs) were reduced in GH-deficient animals. This effect corresponds with differences in AOM-induced proliferation, but not apoptosis. These data indicate that GH is required for the full effect of AOM on colon ACF and tumor development, and that the SDR rat is a promising model for studies regarding the role of GH/IGF system in the initiation and promotion of colon cancer.
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Affiliation(s)
- Robert E Carroll
- Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
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19
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Ishibe S, Karihaloo A, Ma H, Zhang J, Marlier A, Mitobe M, Togawa A, Schmitt R, Czyczk J, Kashgarian M, Geller DS, Thorgeirsson SS, Cantley LG. Met and the epidermal growth factor receptor act cooperatively to regulate final nephron number and maintain collecting duct morphology. Development 2009; 136:337-45. [PMID: 19103805 DOI: 10.1242/dev.024463] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ureteric bud (UB) branching during kidney development determines the final number of nephrons. Although hepatocyte growth factor and its receptor Met have been shown to stimulate branching morphogenesis in explanted embryonic kidneys, loss of Met expression is lethal during early embryogenesis without obvious kidney abnormalities. Met(fl/fl);HoxB7-Cre mice, which lack Met expression selectively in the UB, were generated and found to have a reduction in final nephron number. These mice have increased Egf receptor expression in both the embryonic and adult kidney, and exogenous Egf can partially rescue the branching defect seen in kidney explants. Met(fl/fl);HoxB7-Cre;wa-2/wa-2 mice, which lack normal Egfr and Met signaling, exhibit small kidneys with a marked decrease in UB branching at E14.5 as well as a reduction in final glomerular number. These mice developed progressive interstitial fibrosis surrounding collecting ducts with kidney failure and death by 3-4 weeks of age. Thus, in support of previous in vitro findings, Met and the Egf receptor can act cooperatively to regulate UB branching and mediate maintenance of the normal adult collecting duct.
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Affiliation(s)
- Shuta Ishibe
- Section of Nephrology, Yale University School of Medicine, New Haven, CT 06510, USA.
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20
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Macrophage migration inhibitory factor and interleukin-8 produced by gastric epithelial cells during Helicobacter pylori exposure induce expression and activation of the epidermal growth factor receptor. Infect Immun 2008; 76:3233-40. [PMID: 18474653 DOI: 10.1128/iai.01534-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
While a link between Helicobacter pylori exposure and gastric cancer has been established, the underlying mechanisms remain unclear. H. pylori induces a chronic inflammatory response in infected individuals. A link between chronic inflammation and carcinogenesis has long been suggested but never elucidated. Epidermal growth factor receptor (EGFR) signaling plays an important role in both proinflammatory and procarcinogenic mechanisms and is upregulated on gastric epithelial cells (GECs) during H. pylori exposure. The aim of this study was to examine the effects of two important proinflammatory cytokines released during H. pylori infection, macrophage migration inhibitory factor (MIF) and interleukin-8 (IL-8), on the expression and transactivation of EGFR and on the proliferation of GECs during H. pylori exposure. The expression of EGFR by GECs was increased by exposure to either H. pylori, recombinant MIF, or recombinant IL-8. However, cag pathogenicity island knockout strains of H. pylori had very little effect on expression. MIF and IL-8 also induced phosphorylation of EGFR, signaling events, and proliferation during H. pylori exposure, all of which were decreased when they were neutralized by these cytokines or were blocked from their receptors. The overall role of EGFR in these responses to H. pylori exposure was assessed by knocking down EGFR expression by small interfering RNA.
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21
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Tan TT, White E. Therapeutic Targeting of Death Pathways in Cancer: Mechanisms for Activating Cell Death in Cancer Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 615:81-104. [DOI: 10.1007/978-1-4020-6554-5_5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Soma D, Kitayama J, Yamashita H, Miyato H, Ishikawa M, Nagawa H. Leptin augments proliferation of breast cancer cells via transactivation of HER2. J Surg Res 2007; 149:9-14. [PMID: 18262553 DOI: 10.1016/j.jss.2007.10.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 08/14/2007] [Accepted: 10/05/2007] [Indexed: 11/27/2022]
Abstract
Excessive fat mass is a risk factor for postmenopausal breast cancer. Leptin, a fat cell-derived peptide hormone, elicits a growth-stimulating effect in breast cancer cells with leptin receptor expression, although the leptin-induced signal in malignant cells is not fully understood. Here, we found that exogenous leptin induced tyrosine phosphorylation of HER2 in SKBR3 cells, which showed marked overexpression of HER2. Phosphorylation of HER2 was detected at 2 min and continued up to 120 min after the start of stimulation. Leptin-induced HER2 phosphorylation was partially reduced by an epidermal growth factor receptor inhibitor, AG1478, or a Janus-activated kinase inhibitor, AG490. Leptin also induced phosphorylation of extracellular signal-regulated kinase 1/2, which was mostly abrogated by a HER2 tyrosine kinase inhibitor, AG825. In a proliferation assay, addition of 500 ng/mL leptin increased the proliferation of SKBR3, which was totally inhibited by AG825. Collectively, our data suggest that leptin can transactivate HER2 through both epidermal growth factor receptor and Janus-activated kinase 2 activation, which can cause the growth of breast cancer cells with HER2 overexpression.
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Affiliation(s)
- Daisuke Soma
- Department of Surgery, Division of Surgical Oncology, University of Tokyo, Tokyo, Japan.
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23
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Ghazani AA, Arneson N, Warren K, Pintilie M, Bayani J, Squire JA, Done SJ. Genomic alterations in sporadic synchronous primary breast cancer using array and metaphase comparative genomic hybridization. Neoplasia 2007; 9:511-20. [PMID: 17603634 PMCID: PMC1899252 DOI: 10.1593/neo.07301] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Revised: 05/03/2007] [Accepted: 05/03/2007] [Indexed: 01/19/2023] Open
Abstract
Synchronous primary breast cancer describes the occurrence of multiple tumors affecting one or both breasts at initial diagnosis. This provides a unique opportunity to identify tissue-specific genomic markers that characterize each tumor while controlling for the individual genetic background of a patient. The aim of this study was to examine the genomic alterations and degree of similarity between synchronous cancers. Using metaphase comparative genomic hybridization and array comparative genomic hybridization (aCGH), the genomic alterations of 23 synchronous breast cancers from 10 patients were examined at both chromosomal and gene levels. Synchronous breast cancers, when compared to their matched counterparts, were found to have a common core set of genetic alterations, with additional unique changes present in each. They also frequently exhibited features distinct from the more usual solitary primary breast cancers. The most frequent genomic alterations included chromosomal gains of 1q, 3p, 4q, and 8q, and losses of 11q, 12q, 16q, and 17p. aCGH identified copy number amplification in regions that are present in all 23 tumor samples, including 1p31.3-1p32.3 harboring JAK1. Our findings suggest that synchronous primary breast cancers represent a unique type of breast cancer and, at least in some instances, one tumor may give rise to the other.
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MESH Headings
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/pathology
- Chromosome Aberrations
- Chromosomes, Human
- DNA, Neoplasm
- Genome, Human
- Humans
- In Situ Hybridization, Fluorescence
- Lasers
- Metaphase
- Microdissection
- Mitosis
- Neoplasm Invasiveness/genetics
- Neoplasm Invasiveness/pathology
- Nucleic Acid Hybridization
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tissue Array Analysis
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Affiliation(s)
- Arezou A Ghazani
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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24
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Huang Y, Li X, Jiang J, Frank SJ. Prolactin modulates phosphorylation, signaling and trafficking of epidermal growth factor receptor in human T47D breast cancer cells. Oncogene 2006; 25:7565-76. [PMID: 16785991 DOI: 10.1038/sj.onc.1209740] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Prolactin (PRL) is a polypeptide hormone produced by the anterior pituitary gland and other sites that acts both systemically and locally to cause lactation and other biological effects by interacting with the PRL receptor, a Janus kinase (JAK)2-coupled cytokine receptor family member, and activating downstream signal pathways. Recent evidence suggests PRL is a player in the pathogenesis and progression of breast cancer. Epidermal growth factor (EGF) also has effects on breast tissue, working through its receptors, epidermal growth factor receptor (EGFR) and ErbB-2 (c-neu, HER2), both intrinsic tyrosine kinase growth factor receptors. EGFR promotes pubertal breast ductal morphogenesis in mice, and both EGFR and ErbB-2 are relevant in pathogenesis and behavior of breast and other human cancers. Previous studies showed that PRL and EGF synergize to enhance motility in the human breast cancer cell line, T47D. In this study, we explored crosstalk between the PRL and EGF signaling pathways in T47D cells, with an ultimate aim of understanding how these two important factors might work together in vivo to affect breast cancer behavior. Both PRL and EGF caused robust signaling in T47D cells; PRL acutely activated JAK2, signal transducer and activator of transcription-5 (STAT5), and extracellular signal-regulated kinase-1 and -2 (ERK1 and ERK2), whereas EGF caused EGFR activation and consequent src homology collagen (SHC) activation and ERK activation. Notably, PRL also caused phosphorylation of the EGFR and ErbB-2 at sites detected by PTP101, an antibody that recognizes threonine phosphorylation at consensus motifs for ERK-induced phosphorylation. PRL-induced PTP101-reactive phosphorylation was prevented by pretreatment with PD98059, an ERK pathway inhibitor. Furthermore, PRL synergized with EGF in activating SHC and ERK and transactivating a luciferase reporter driven by c-fos gene enhancer elements, suggesting that PRL allowed markedly enhanced EGF signaling. This was accompanied by substantial inhibition of EGF-induced EGFR downregulation when PRL and EGF cotreatment was compared to EGF treatment alone. This effect of PRL was abrogated by ERK pathway inhibitor pretreatment. Our data suggest that PRL synergistically augments EGF signaling in T47D breast cancer cells at least in part by lessening EGF-induced EGFR downregulation and that this effect requires PRL-induced ERK activity and threonine phosphorylation of EGFR.
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Affiliation(s)
- Y Huang
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA
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25
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Scott HJ, Stebbing MJ, Walters CE, McLenachan S, Ransome MI, Nichols NR, Turnley AM. Differential effects of SOCS2 on neuronal differentiation and morphology. Brain Res 2006; 1067:138-45. [PMID: 16360125 DOI: 10.1016/j.brainres.2005.10.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 10/14/2005] [Accepted: 10/15/2005] [Indexed: 10/25/2022]
Abstract
Neuronal differentiation of neural progenitor cells is regulated by a variety of growth and transcription factors, that not only regulate cell fate of the progenitor cells but that can also regulate neuronal morphology. Suppressor of cytokine signaling-2 (SOCS2) is an intracellular regulator of Growth Hormone (GH) signaling that is expressed in neural stem cells and neurons during development and is required to overcome the inhibitory effects of GH on neuronal differentiation. SOCS2 also promotes neurite outgrowth, however, whether the mechanism by which SOCS2 regulates neuronal differentiation and neurite outgrowth is the same is not clear. Furthermore, whether the over-expression of SOCS2 has physiological in addition to morphological effects is unknown. To address these questions, we differentiated adult neural progenitor cells derived from wildtype C57BL/6 or SOCS2 over-expressing transgenic mice (SOCS2Tg) in the presence or absence of GH and determined effects on neuronal differentiation and morphology. Compared to wildtype cells, differentiation of SOCS2Tg neurospheres resulted in increased neurogenesis, which was not inhibited by GH. The neurons derived from these cells appeared more complex, with increased neurite outgrowth and number. GH did not, however, have any effect on neurite outgrowth of wildtype or SOCS2Tg neurons. Furthermore, basic electrophysiological analysis of wildtype and SOCS2Tg neurons derived from the neurospheres showed that they were both of an immature electrophysiological neuronal phenotype, indicating that although SOCS2 expression can regulate neuronal morphology, it appears to have little effect on neuronal ion channel expression.
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Affiliation(s)
- Hannah J Scott
- Neural Regeneration Laboratory, Centre for Neuroscience, The University of Melbourne, Grattan St., Parkville, Victoria 3010, Australia
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26
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Dharmawardana PG, Peruzzi B, Giubellino A, Burke TR, Bottaro DP. Molecular targeting of growth factor receptor-bound 2 (Grb2) as an anti-cancer strategy. Anticancer Drugs 2006; 17:13-20. [PMID: 16317285 DOI: 10.1097/01.cad.0000185180.72604.ac] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Growth factor receptor-bound 2 (Grb2) is a ubiquitously expressed adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway. As such, it has been implicated in the oncogenesis of several important human malignancies. In addition to this function, research over the last decade has revealed other fundamental roles for Grb2 in cell motility and angiogenesis--processes that also contribute to tumor growth, invasiveness and metastasis. This functional profile makes Grb2 a high priority target for anti-cancer drug development. Knowledge of Grb2 protein structure, its component Src homology domains and their respective structure-function relationships has facilitated the rapid development of sophisticated drug candidates that can penetrate cells, bind Grb2 with high affinity and potently antagonize Grb2 signaling. These novel compounds offer considerable promise in our growing arsenal of rationally designed anti-cancer therapeutics.
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Affiliation(s)
- Pathirage G Dharmawardana
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1107, USA
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Abstract
Despite decades of cancer research, mortality rates remain high largely due to the failure of early detection, poor understanding of the epidemiology of rational drug targets, and molecular etiology of human cancers. The discovery of disease markers promises to deliver some solutions to these formidable challenges. Gene and protein expression profiling through DNA microarray and proteomics have already made a tremendous effect in this area. However, protein/gene expression does not necessarily reflect protein activity, which is often regulated via post-translation modifications, of which phosphorylation is one of the most prominent. This is an important consideration because the activity of protein is a more relevant phenotype than its expression during pathogenesis. Tyrosine kinases represent a very important class of enzymes that are critical regulators of mitogenic and angiogenic signaling, hence attractive targets for anticancer drugs as exemplified by BCR-ABL and ErbB2. More than 50% of them are overexpressed or mutated resulting in a gain of function in various human cancers. In this review, we discuss the potential effect of phosphoproteins as cancer markers in cancer diagnosis and therapeutics. Phosphoproteomics strategies that might pave the way to high-throughput analysis for routine clinical applications are also described.
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Affiliation(s)
- Yoon Pin Lim
- Oncology Research Institute, National University Medical Institutes, National University of Singapore, Singapore, Republic of Singapore.
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28
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Boerner JL, Biscardi JS, Silva CM, Parsons SJ. Transactivating agonists of the EGF receptor require Tyr 845 phosphorylation for induction of DNA synthesis. Mol Carcinog 2005; 44:262-73. [PMID: 16167350 DOI: 10.1002/mc.20138] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Signaling networks play important roles in cancer progression. For example, overexpression of the epidermal growth factor receptor (EGFR) is a poor prognostic indicator in multiple tumor types. Recent studies have postulated that the EGFR functions as a central conduit for signaling by different classes of cell surface receptors. In this study, we demonstrated that c-Src-dependent phosphorylation of tyrosine 845 (Tyr 845) on EGFR was required for DNA synthesis induced by the G protein-coupled agonists, endothelin (ET) and lysophosphatidic acid (LPA), and the cytokine, growth hormone (GH), in murine fibroblast and breast cancer model systems. In addition, we showed that a dominant interfering form of signal transducer and activator of transcription (STAT)5b (a downstream effector of phospho-Tyr 845 [pY845] in fibroblasts) abrogates DNA synthesis induced by all agonists in the breast cancer model. To further characterize the role of Tyr 845, a pY845-containing peptide was microinjected into SKBr3 breast cancer cells and murine fibroblasts, and was found to ablate EGF-stimulated S-phase entry in both cell systems. Taken together, these findings suggested that pY845 is critical for DNA synthesis induced by a variety of mitogens and that its signaling effectors may include but are not limited to STAT5b.
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Affiliation(s)
- Julie L Boerner
- Department of Microbiology, The Cancer Center, University of Virginia Health System, Charlottesville, Virginia 22908, USA
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Soriano JV, Liu N, Gao Y, Yao ZJ, Ishibashi T, Underhill C, Burke TR, Bottaro DP. Inhibition of angiogenesis by growth factor receptor bound protein 2-Src homology 2 domain bound antagonists. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1289.3.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Abstract
Growth factor receptor bound protein 2 (Grb2) is an intracellular adaptor protein that participates in the signal transduction cascades of several angiogenic factors, including hepatocyte growth factor, basic fibroblast growth factor, and vascular endothelial growth factor. We described previously the potent blockade of hepatocyte growth factor–stimulated cell motility, matrix invasion, and epithelial tubulogenesis by synthetic Grb2-Src homology 2 (SH2) domain binding antagonists. Here, we show that these binding antagonists block basic morphogenetic events required for angiogenesis, including hepatocyte growth factor–, vascular endothelial growth factor–, and basic fibroblast growth factor–stimulated endothelial cell proliferation and migration, as well as phorbol 12-myristate 13-acetate–stimulated endothelial cell migration and matrix invasion. The Grb2-SH2 domain binding antagonists also impair angiogenesis in vitro, as shown by the inhibition of cord formation by macrovascular endothelial cells on Matrigel. We further show that a representative compound inhibits angiogenesis in vivo as measured using a chick chorioallantoic membrane assay. These results suggest that Grb2 is an important mediator of key proangiogenic events, with potential application to pathologic conditions where neovascularization contributes to disease progression. In particular, the well-characterized role of Grb2 in signaling cell cycle progression together with our present findings suggests that Grb2-SH2 domain binding antagonists have the potential to act as anticancer drugs that target both tumor and vascular cell compartments.
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Affiliation(s)
| | - Ningfei Liu
- 4Department of Cell Biology, Georgetown University, Washington, District of Columbia
| | - Yang Gao
- 2Medicinal Chemistry, National Cancer Institute, NIH, Bethesda, Maryland
| | - Zhu-Jun Yao
- 2Medicinal Chemistry, National Cancer Institute, NIH, Bethesda, Maryland
| | - Toshio Ishibashi
- 3Department of Otolaryngology, Social Insurance Central General Hospital, Tokyo, Japan; and
| | - Charles Underhill
- 4Department of Cell Biology, Georgetown University, Washington, District of Columbia
| | - Terrence R. Burke
- 2Medicinal Chemistry, National Cancer Institute, NIH, Bethesda, Maryland
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Argetsinger LS, Kouadio JLK, Steen H, Stensballe A, Jensen ON, Carter-Su C. Autophosphorylation of JAK2 on tyrosines 221 and 570 regulates its activity. Mol Cell Biol 2004; 24:4955-67. [PMID: 15143187 PMCID: PMC416404 DOI: 10.1128/mcb.24.11.4955-4967.2004] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The tyrosine kinase JAK2 is a key signaling protein for at least 20 receptors in the cytokine/hematopoietin receptor superfamily and is a component of signaling by insulin receptor and several G-protein-coupled receptors. However, there is only limited knowledge of the physical structure of JAK2 or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are autophosphorylated. Phosphorylation of tyrosine 570 is particularly robust. In response to growth hormone, JAK2 was rapidly and transiently phosphorylated at tyrosines 221 and 570, returning to basal levels by 60 min. Analysis of the sequences surrounding tyrosines 221 and 570 in JAK2 and tyrosines in other proteins that are phosphorylated in response to ligands that activate JAK2 suggests that the YXX[L/I/V] motif is one of the motifs recognized by JAK2. Experiments using JAK2 with tyrosines 221 and 570 mutated to phenylalanine suggest that tyrosines 221 and 570 in JAK2 may serve as regulatory sites in JAK2, with phosphorylation of tyrosine 221 increasing kinase activity and phosphorylation of tyrosine 570 decreasing kinase activity and thereby contributing to rapid termination of ligand activation of JAK2.
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Affiliation(s)
- Lawrence S Argetsinger
- Department of Molecular and Integrative Physiology, The University of Michigan Medical School, Ann Arbor, MI 48109-0622, USA
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31
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Kurzer JH, Argetsinger LS, Zhou YJ, Kouadio JLK, O'Shea JJ, Carter-Su C. Tyrosine 813 is a site of JAK2 autophosphorylation critical for activation of JAK2 by SH2-B beta. Mol Cell Biol 2004; 24:4557-70. [PMID: 15121872 PMCID: PMC400461 DOI: 10.1128/mcb.24.10.4557-4570.2004] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The tyrosine kinase Janus kinase 2 (JAK2) binds to the majority of the known members of the cytokine family of receptors. Ligand-receptor binding leads to activation of the associated JAK2 molecules, resulting in rapid autophosphorylation of multiple tyrosines within JAK2. Phosphotyrosines can then serve as docking sites for downstream JAK2 signaling molecules. Despite the importance of these phosphotyrosines in JAK2 function, only a few sites and binding partners have been identified. Using two-dimensional phosphopeptide mapping and a phosphospecific antibody, we identified tyrosine 813 as a site of JAK2 autophosphorylation of overexpressed JAK2 and endogenous JAK2 activated by growth hormone. Tyrosine 813 is contained within a YXXL sequence motif associated with several other identified JAK2 phosphorylation sites. We show that phosphorylation of tyrosine 813 is required for the SH2 domain-containing adapter protein SH2-B beta to bind JAK2 and to enhance the activity of JAK2 and STAT5B. The homologous tyrosine in JAK3, tyrosine 785, is autophosphorylated in response to interleukin-2 stimulation and is required for SH2-B beta to bind JAK3. Taken together these data strongly suggest that tyrosine 813 is a site of autophosphorylation in JAK2 and is the SH2-B beta-binding site within JAK2 that is required for SH2-B beta to enhance activation of JAK2.
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Affiliation(s)
- Jason H Kurzer
- Graduate Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0662, USA
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32
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Morgan E, Varro R, Sepulveda H, Ember JA, Apgar J, Wilson J, Lowe L, Chen R, Shivraj L, Agadir A, Campos R, Ernst D, Gaur A. Cytometric bead array: a multiplexed assay platform with applications in various areas of biology. Clin Immunol 2004; 110:252-66. [PMID: 15047203 DOI: 10.1016/j.clim.2003.11.017] [Citation(s) in RCA: 359] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 11/10/2003] [Indexed: 11/29/2022]
Abstract
The introduction of flow cytometric bead-based technology has added a new approach for investigators to simultaneously measure multiple analytes in biological and environmental samples. This new technology allows for (1) evaluation of multiple analytes in a single sample; (2) utilization of minimal sample volumes to glean data; (3) reproducibility and results comparative with previous experiments; (4) direct comparison with existing assays; and (5) a more rapid evaluation of multiple samples in a single platform. The cytometric bead array (CBA) system enables simultaneous measurement of multiple analytes in sample volumes too small for traditional immunoassays. Results have been presented for the analysis of a variety of human cytokines. In addition, the technology allows for the design and creation of assays to measure a variety of analytes including inflammatory mediators, chemokines, immunoglobulin isotypes, intracellular signaling molecules, apoptotic mediators, adhesion molecules, and antibodies. New initiatives put forward by the Human Genome Project and the FDA require the development and use of assays for the rapid simultaneous quantitation of multiple analytes. The CBA technology provides the ability to quantify multiple proteins within a given sample, with precision and consistency.
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33
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Peace BE, Hill KJ, Degen SJF, Waltz SE. Cross-talk between the receptor tyrosine kinases Ron and epidermal growth factor receptor. Exp Cell Res 2003; 289:317-25. [PMID: 14499632 DOI: 10.1016/s0014-4827(03)00280-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heterogeneous receptor-receptor interactions may play a role in intracellular signaling. Accordingly, the interaction of two dissimilar tyrosine kinase receptors, Ron and epidermal growth factor receptor (EGFR) was investigated. The functional interaction of Ron and EGFR in cell scatter and oncogenic transformation was investigated in vivo. Transfection of a dominant negative form of EGFR into human embryonic kidney cells stably expressing Ron (293-Ron) dramatically reduced the scatter response induced by the Ron ligand hepatocyte growth factor-like protein/macrophage stimulating protein (HGFL). The scatter response of the 293-Ron cells was also attenuated by treatment of the cells with the specific EGFR inhibitor AG 1478. Co-transfection of Ron and dominant-negative EGFR, or co-transfection of EGFR and a dominant-negative form of Ron reduced focus formation in NIH/3T3 cells. Western analysis of NIH/3T3 cells overexpressing murine Ron and expressing endogenous levels of EGFR was used to demonstrate that Ron and EGFR co-immunoprecipitate. Stimulation of the cells in vitro with the Ron ligand HGFL or with the EGFR ligand epidermal growth factor (EGF) appeared to induce phosphorylation of both receptors. Co-immunoprecipitation and phosphorylation of phosphatidyl inositol 3-kinase (PI3-K) was also observed. This novel finding of a functional and biochemical interaction between Ron and EGFR suggests that heterologous tyrosine kinase receptor interactions may play a role in cellular processes such as scatter and transformation.
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Affiliation(s)
- Belinda E Peace
- Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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34
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Chow JYC, Carlstrom K, Barrett KE. Growth hormone reduces chloride secretion in human colonic epithelial cells via EGF receptor and extracellular regulated kinase. Gastroenterology 2003; 125:1114-24. [PMID: 14517795 DOI: 10.1016/s0016-5085(03)01211-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND AND AIMS Growth hormone (GH) has been shown to alleviate symptoms in patients with Crohn's disease. Chloride secretion is important in driving intestinal fluid secretion. We examined whether GH inhibits chloride secretion induced by carbachol (CCh, a calcium-dependent pathway), and the downstream effectors responsible. METHODS T(84) cells were pretreated with GH at various concentrations followed by CCh (100 micromol/L). Chloride secretion was assessed as changes in short circuit current ( triangle up I(sc)) in Ussing chambers. Tyrphostins AG1478 (an epidermal growth factor receptor [EGFr] inhibitor) and AG490 (a Janus kinase 2 [JAK2] inhibitor), SB203580 (a p38 inhibitor), and PD98059 (a MEK1 inhibitor) were used. RESULTS GH inhibited CCh-induced chloride secretion at up to 10 nmol/L, but higher concentrations were less effective. GH caused tyrosine phosphorylation of JAK2 and EGFr. AG490 suppressed activation of JAK2 and EGFr in response to GH. AG1478 prevented GH activation of EGFr and reversed its inhibitory effect on chloride secretion. GH also induced activation of both p38 and ERK1/2. AG490 reversed GH-induced tyrosine phosphorylation of both ERK1/2 and p38, but AG1478 reversed that of ERK1/2 only. PD98059, but not SB203580, reversed the inhibitory effect of GH on chloride secretion. CONCLUSIONS GH inhibits CCh-induced chloride secretion via a JAK2-dependent mechanism involving transactivation of EGFr and consequent recruitment of ERK1/2. Although activated, p38 does not contribute to the inhibitory effect of GH on secretion. These data elucidate mechanisms of GH inhibition of chloride secretion in intestinal epithelia, which may be relevant to therapeutic benefits of GH in Crohn's disease or other diarrheal diseases.
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Affiliation(s)
- Jimmy Y C Chow
- Division of Gastroenterology, Department of Medicine, University of California, San Diego, School of Medicine, San Diego, California, USA
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35
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Blake TJ, Jenkins BJ, D’Andrea RJ, Gonda TJ. Functional cross‐talk between cytokine receptors revealed by activating mutations in the extracellular domain of the β‐subunit of the GM‐CSF receptor. J Leukoc Biol 2002. [DOI: 10.1189/jlb.72.6.1246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Timothy J. Blake
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, and Department of Medicine, Adelaide University, South Australia
| | - Brendan J. Jenkins
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, and Department of Medicine, Adelaide University, South Australia
| | - Richard J. D’Andrea
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, and Department of Medicine, Adelaide University, South Australia
| | - Thomas J. Gonda
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, and Department of Medicine, Adelaide University, South Australia
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36
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Ray EC, Avissar NE, Sax HC. Growth factor regulation of enterocyte nutrient transport during intestinal adaptation. Am J Surg 2002; 183:361-71. [PMID: 11975923 DOI: 10.1016/s0002-9610(02)00805-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Intestinal adaptation occurs in response to injury or alteration in nutrient availability. It is both morphologic and physiologic in nature and can be mediated by growth factors and nutrients. Pathologic conditions such as short-bowel syndrome and inflammatory bowel disease lead to derangements in nutrient absorption that may exceed the body's regenerative and adaptive capacity. Failure to fully adapt often results in long-term dependence on parenteral nutrition, leading to decreased quality of life and excessive medical expenses. The therapeutic use of appropriate growth factors may increase the adaptive capabilities of the gut. DATA SOURCE Medline and current literature review. CONCLUSIONS The major known nutrient transporters present in the gut and the mechanisms by which growth factors alter transport activity during intestinal adaptation are summarized. Growth factors have the potential to improve nutrient absorption in some bowel diseases.
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Affiliation(s)
- Edward C Ray
- Department of Surgery, University of Rochester School of Medicine and Dentistry, Box SURG, 601 Elmwood Avenue, Rochester, NY 14642, USA
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37
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Saito Y, Haendeler J, Hojo Y, Yamamoto K, Berk BC. Receptor heterodimerization: essential mechanism for platelet-derived growth factor-induced epidermal growth factor receptor transactivation. Mol Cell Biol 2001; 21:6387-94. [PMID: 11533228 PMCID: PMC99786 DOI: 10.1128/mcb.21.19.6387-6394.2001] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies showed that the epidermal growth factor receptor (EGFR) can be transactivated by platelet-derived growth factor (PDGF) stimulation and that EGFR transactivation is required for PDGF-stimulated cell migration. To investigate the mechanism for cross talk between the PDGF beta receptor (PDGFbetaR) and the EGFR, we stimulated rat aortic vascular smooth muscle cells (VSMC) with 20 ng of PDGF/ml. Transactivation of the EGFR, defined by receptor tyrosine phosphorylation, occurred with the same time course as PDGFbetaR activation. Basal formation of PDGFbetaR-EGFR heterodimers was shown by coimmunoprecipitation studies, and interestingly, disruption of this receptor heterodimer abolished EGFR transactivation. Breakdown of the heterodimer was observed when VSMC were pretreated with antioxidants or with a Src family kinase inhibitor. Disruption of heterodimers decreased ERK1 and ERK2 activation by PDGF. Although PDGF-induced PDGFbetaR activation was abolished after pretreatment with 1 microM AG1295 (a specific PDGF receptor kinase inhibitor), EGFR transactivation was still observed, indicating that PDGFbetaR kinase activity is not required. In conclusion, our data demonstrate that the PDGFbetaR and the EGFR form PDGFbetaR-EGFR heterodimers basally, and we suggest that heterodimers represent a novel signaling complex which plays an important role in PDGF signal transduction.
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MESH Headings
- 1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt/pharmacology
- Acetylcysteine/pharmacology
- Animals
- Cells, Cultured
- Dimerization
- ErbB Receptors/metabolism
- Free Radical Scavengers/pharmacology
- Male
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/metabolism
- Models, Biological
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Platelet-Derived Growth Factor/pharmacology
- Protein Tyrosine Phosphatases/physiology
- Rats
- Rats, Sprague-Dawley
- Receptor Cross-Talk
- Receptor, Platelet-Derived Growth Factor beta/metabolism
- Transcriptional Activation
- src-Family Kinases/physiology
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Affiliation(s)
- Y Saito
- Center for Cardiovascular Research, University of Rochester, Rochester, New York 14642, USA
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38
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Aman MJ, Walk SF, March ME, Su HP, Carver DJ, Ravichandran KS. Essential role for the C-terminal noncatalytic region of SHIP in FcgammaRIIB1-mediated inhibitory signaling. Mol Cell Biol 2000; 20:3576-89. [PMID: 10779347 PMCID: PMC85650 DOI: 10.1128/mcb.20.10.3576-3589.2000] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The inositol phosphatase SHIP binds to the FcgammaRIIB1 receptor and plays a critical role in FcgammaRIIB1-mediated inhibition of B-cell proliferation and immunoglobulin synthesis. The molecular details of SHIP function are not fully understood. While point mutations of the signature motifs in the inositol phosphatase domain abolish SHIP's ability to inhibit calcium flux in B cells, little is known about the function of the evolutionarily conserved, putative noncatalytic regions of SHIP in vivo. In this study, through a systematic mutagenesis approach, we identified the inositol phosphatase domain of SHIP between amino acids 400 and 866. Through reconstitution of a SHIP-deficient B-cell line with wild-type and mutant forms of SHIP, we demonstrate that the catalytic domain alone is not sufficient to mediate FcgammaRIIB1/SHIP-dependent inhibition of B-cell receptor signaling. Expression of a truncation mutant of SHIP that has intact phosphatase activity but lacks the last 190 amino acids showed that the noncatalytic region in the C terminus is essential for inhibitory signaling. Mutation of two tyrosines within this C-terminal region, previously identified as important in binding to Shc, showed a reduced inhibition of calcium flux. However, studies with an Shc-deficient B-cell line indicated that Shc-SHIP complex formation is not required and that other proteins that bind these tyrosines may be important in FcgammaRIIB1/SHIP-mediated calcium inhibition. Interestingly, membrane targeting of SHIP lacking the C terminus is able to restore this inhibition, suggesting a role for the C terminus in localization or stabilization of SHIP interaction at the membrane. Taken together, these data suggest that the noncatalytic carboxyl-terminal 190 amino acids of SHIP play a critical role in SHIP function in B cells and may play a similar role in several other receptor systems where SHIP functions as a negative regulator.
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Affiliation(s)
- M J Aman
- Beirne B. Carter Center for Immunology Research and the Department of Microbiology, University of Virginia, Charlottesville, Virginia 22908, USA
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39
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D'Andrea RJ, Gonda TJ. A model for assembly and activation of the GM-CSF, IL-3 and IL-5 receptors: insights from activated mutants of the common beta subunit. Exp Hematol 2000; 28:231-43. [PMID: 10720688 DOI: 10.1016/s0301-472x(99)00159-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Granulocyte-macrophage colony stimulating factor (GM-CSF), Interleukin-3 (IL-3) and Interleukin-5 (IL-5) have overlapping, pleiotropic effects on hematopoietic cells, including neutrophils, eosinophils, monocytes and early progenitor cells. The high-affinity receptors for human GM-CSF, IL-3, and IL-5 share a common beta-subunit (hbeta(c)), which is essential for signalling and plays a major role in recruiting intracellular signalling molecules. While activation of the cytoplasmic tyrosine kinase JAK2 appears to be the initiating event for signalling, the immediate events that trigger this are still unclear. We have isolated a number of activated mutants of hbeta(c), which can be grouped into classes defined by their state of receptor phosphorylation, their requirement for alpha subunit as a cofactor, and their activities in primary cells and cell lines. We discuss these findings with regard to the stoichiometry, activation, and signalling of the normal GM-CSF/IL-3/IL-5 receptor complexes. Specifically, this work has implications for the role of the ligand-specific alpha-subunits in initiating the signalling through the beta-subunit, the role of beta subunit dimerization as a receptor trigger, and the function of receptor tyrosine phosphorylation in generating growth and survival signals. Based on the properties of the activated mutants and the recent structures of erythropoietin receptor (Epo-R) complexes, we propose a model in which (1) activation of hbeta(c) can occur via alternative states that differ with respect to stoichiometry and subunit assembly, but which all mediate proliferative responses, and (2) each of the different classes of activated mutants mimics one of these alternative states.
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MESH Headings
- Amino Acid Sequence
- Animals
- Granulocyte-Macrophage Colony-Stimulating Factor/metabolism
- Humans
- Interleukin-3/metabolism
- Interleukin-5/metabolism
- Models, Biological
- Models, Molecular
- Molecular Sequence Data
- Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/chemistry
- Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics
- Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism
- Receptors, Interleukin/chemistry
- Receptors, Interleukin/genetics
- Receptors, Interleukin/metabolism
- Receptors, Interleukin-3/chemistry
- Receptors, Interleukin-3/genetics
- Receptors, Interleukin-3/metabolism
- Receptors, Interleukin-5
- Signal Transduction
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Affiliation(s)
- R J D'Andrea
- Hanson Centre for Cancer Research and, Adelaide, South Australia, Australia
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40
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Kim SO, Houtman JC, Jiang J, Ruppert JM, Bertics PJ, Frank SJ. Growth hormone-induced alteration in ErbB-2 phosphorylation status in 3T3-F442A fibroblasts. J Biol Chem 1999; 274:36015-24. [PMID: 10585492 DOI: 10.1074/jbc.274.50.36015] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The growth hormone receptor (GHR), a cytokine receptor superfamily member, requires the JAK2 tyrosine kinase for signaling. We now examine functional interactions between growth hormone (GH) and epidermal growth factor (EGF) in 3T3-F442A fibroblasts. Although EGF enhanced ErbB-2 tyrosine phosphorylation, GH, while causing retardation of its migration on SDS-polyacrylamide gel electrophoresis, decreased ErbB-2's tyrosine phosphorylation. GH-induced retardation was reversed by treatment of anti-ErbB-2 precipitates with both alkaline phosphatase and protein phosphatase 2A, suggesting that GH induced serine/threonine phosphorylation of ErbB-2. Both GH-induced shift in ErbB-2 migration and GH-induced MAP kinase activation were unaffected by a protein kinase C inhibitor but were blocked by the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1 (MEK1) inhibitor, PD98059. Notably, leukemia inhibitory factor, but not interferon-gamma, also promoted ErbB-2 shift and mitogen-activated protein kinase activation. Cotreatment with EGF and GH versus EGF alone resulted in a 35% decline in acute ErbB-2 tyrosine 1248 autophosphorylation, a marked decline (approximately 50%) in DNA synthesis, and substantially decreased cyclin D1 expression. We conclude that in 3T3-F442A cells, 1) the GH-induced decrease in ErbB-2 tyrosine phosphorylation correlates with MEK1/mitogen-activated protein kinase activity and 2) GH antagonizes EGF-induced DNA synthesis and cyclin D1 expression in a pattern consistent with its alteration in ErbB-2 phosphorylation status.
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Affiliation(s)
- S O Kim
- Department of Medicine, University of Alabama at Birmingham, AL 35294, USA
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41
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Larrea F, Sánchez-González S, Méndez I, García-Becerra R, Cabrera V, Ulloa-Aguirre A. G protein-coupled receptors as targets for prolactin actions. Arch Med Res 1999; 30:532-43. [PMID: 10714368 DOI: 10.1016/s0188-0128(99)00056-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Prolactin (PRL) is known to be involved in a wide range of biological functions including osmoregulation, lactation, reproduction, and immunomodulation. The first step in PRL action involves its interaction with a specific membrane receptor that belongs to the cytokine receptor superfamily. In spite of the lack of a kinase domain, receptors of the cytokine superfamily induce tyrosine phosphorylation of cellular substrates including the receptors. The role of PRL in female reproductive functions is well known and a direct effect on ovarian and testicular steroidogenesis has been established. In the ovary, PRL binds to a specific membrane receptor and exerts an inhibitory effect on follicular steroidogenesis. This effect is the result of an impairment involving FSH stimulation of G protein-coupled receptors (GPCR) and cyclic AMP-mediated activation of aromatase cytochrome P450 gene expression. This observation may indicate a direct connection between tyrosine phosphorylation and follicle-stimulating hormone (FSH) receptor (FSHR) transduction pathways, as is the case for growth factor receptors with intrinsic tyrosine kinase activity, which share several downstream signaling elements with GPCRs. Some studies leading to our understanding of these pathways are reviewed.
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Affiliation(s)
- F Larrea
- Departamento de Biología de la Reproducción, Instituto Nacional de la Nutrición Salvador Zubirán, México, D.F., Mexico.
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